Poster Session B, Sunday, March 24, 8:00 – 10:00 am, Pacific Concourse
The incremental effect of conceptual specificity in minimal sentence composition: MEG evidence
Songhee Kim1, Liina Pylkkänen1; 1New York University
MEG research has shown that at 200-250ms after stimulus onset, activity in the left anterior temporal lobe (LATL) increases in the presence of semantic composition. This effect is sensitive to the conceptual specificity of the input items, suggesting that the composition of complex meaning is modulated by conceptual specificity. As these results have only been demonstrated for noun phrases, we tested the generality of the pattern by expanding the investigation to cover the full sentence, varying specificity in the subject, verb and object positions of simple three-word sentences. 27 participants were visually presented with sentences one word at a time. All positions had two levels of specificity, i.e., general and specific, and at the subject and verb positions, “no word” condition was also added to measure the effect of composition, e.g., ‘employees/waiters/### clean/sweep/### floors/decks’. Our results did not find a main effect of specificity in the LATL but in the left mid-superior temporal cortex (lmSTC), a region implicated for thematic role processing. Some interaction effects of verb and object specificity, and subject and object specificity, were found in the LATL, as well as subject and object specificity in the lmSTC, a pattern that resembles findings in the noun domain. Finally, the effect of subject composition (i.e., subject + verb vs., no subject + verb) was significant in the LATL and lmSTC but not in the left angular gyrus (LAG), suggesting that the LAG is not a combinatory region. Overall, our results support that the LATL is a cross-categorial combinatory region.
Topic Area: LANGUAGE: Semantic